Conventional oral contraceptives are administered on a repeating 28 day cycle. Contraceptive tablet taking generally begins on the fifth day of the menstrual cycle or on the first Sunday after menstruation begins, continues for a total of 21 days and begins again after seven days without contraceptive tablets. The patient thereafter takes a tablet each day for three weeks, takes no contraceptives for one week, and begins another 28 day cycle of three weeks of tablet taking and one week without tablets for the desired duration of contraceptive treatment.
Some physicians prefer to prescribe 21 tablet packages and have the patient go without tablets for seven days each cycle. Other physicians prefer 28 tablet packages containing seven placebo tablets to facilitate proper tablet administration.
The result is that most conventional oral contraceptives are provided in both 21 tablet and 28 tablet dispensers. Each package contains 21 contraceptive tablets. The 28 tablet package additionally contains seven placebo tablets. Thus, retail pharmacies necessarily must carry both package types of each oral contraceptive stocked, thereby increasing inventory costs.
It would be advantageous to eliminate the need for two types of packages for each oral contraceptive.